If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.

Kolivas Pushes New Kernel Responsiveness Patches

02-26-2010, 08:40 AM

Phoronix: Kolivas Pushes New Kernel Responsiveness Patches

Con Kolivas had stopped working on the Linux kernel for two years after he became fed up with the kernel development community, but last year he made a return by introducing the BFS scheduler. The BFS scheduler for the Linux kernel is quite simple in design compared to other schedulers, but it performed fairly well on desktop systems...

Comment

I seriously question the value of what is produced by this guy. Seems to me that more often than not, his work is unusably buggy and makes things explode in MS like frequency. There may be fringe cases that could benefit from a *decent* implementation of some of his ideas, but it is definitely not of benefit for general users. Especially not in the forms he produces them.

Comment

I am particularly suspicious of the 10000Hz patch. A higher tick rate means more overhead. On the other hand, the overhead may still be tolerable on a fast system.

Really, the thing that annoys me the most is system unresponsiveness in the face of high I/O. I can understand that reading a file can take a while if there is a lot of other disk I/O going on, but switching tabs on my browser should not be affected.

Comment

I seriously question the value of what is produced by this guy. Seems to me that more often than not, his work is unusably buggy and makes things explode in MS like frequency. There may be fringe cases that could benefit from a *decent* implementation of some of his ideas, but it is definitely not of benefit for general users. Especially not in the forms he produces them.

i personally consider CK one of few people hacking the kernel that actually understand what "desktop linux" should be about. that's what i respect about him.

i remember the argument about BFS performance back on lkml, which clearly showed that linux developers have little idea of things average users do on their desktops.

don't get me wrong - as much as i value CK, i still don't like his attitude :]

now that he started making kernel patchsets again, his fanboys are probably flocking back (remember them from cfs vs SD flamewars?)

Comment

It's good that he is working on his own implementations of schedulers and so on, so we can overtake them (if they are better) or use them to see bottlenecks in other implementation. It's a good thing that he helps, I can't see a problem with it.

Comment

i personally consider CK one of few people hacking the kernel that actually understand what "desktop linux" should be about. that's what i respect about him.

Agreed. While I am not able to judge his code, I have experienced much better system responsiveness under heavy disk I/O with BFS than with any other scheduler in recent kernels. I also think that the argument that BFS's benefits do not scale well with high number of processors is totally moot since most of us will likely be sitting on machines with eight cores or less for years to come. BFS seems to have gotten more appreciation among the Android hacking crowd than among "traditional" linux hackers and is often available as an option for various ROMs published over at xda-developers.

Comment

Really, the thing that annoys me the most is system unresponsiveness in the face of high I/O. I can understand that reading a file can take a while if there is a lot of other disk I/O going on, but switching tabs on my browser should not be affected.

I asked myself the same question.
From my "investigation" the fault lies also with Firefox. When you "just" switch tabs actually Firefox also reads/writes some files and that's where the unresponsiveness comes from (my hdd has very poor iops).

Comment

I asked myself the same question.
From my "investigation" the fault lies also with Firefox. When you "just" switch tabs actually Firefox also reads/writes some files and that's where the unresponsiveness comes from (my hdd has very poor iops).

Who's talking about Firefox? The problem is more general. 2.6.32 introduced changes in its scheduler (actually inspired by BFS) to make things better. But still, BFS gives better results.